National Diet and Nutrition Survey (NDNS)

Dear «TopLine»,

A few weeks ago «Fill1» completed the first part of the National Diet and Nutrition Survey (NDNS). Thank you for the time and effort «Fill2» have so far put into this important study, your help is very much appreciated.

When you were last visited by the interviewer, you «Fill3» contact you to discuss «Fill4» taking part in stage 2 of the study. In the next few days, a nurse from NatCen Social Research will contact you and will be able to explain more about the second stage of NDNS.

We very much hope that «Fill2» will be willing to help us again with this study. The information «Fill2» have already given us is very useful, but with the extra information obtained from the nurse visit, it will be even more valuable.

All parts of the second stage are optional and «Fill1» can choose to take part in some parts and not others. As a token of our appreciation, we are enclosing a £5 High Street Gift Card as a thank you for agreeing to be contacted by the nurse.

All personal details will be kept strictly confidential and no one looking at the study findings will be able to identify you or your household in any way. Information will only be used for research purposes and food policy planning.

For more information please read the frequently asked questions on the back of this letter. You can also visit: www.nationaldiet.co.uk or call freephone 0800 652 4572.

We hope «Fill2» will be willing to take part – with your help we can gain a better understanding of the diet and nutrition of people in the United Kingdom.

Yours sincerely,

Gillian Swan Health and Wellbeing Directorate Public Health England gillian.swan@phe.gov.uk

Beverley Bates NDNS Research Director NatCen ndns@natcen.ac.uk FREQUENTLY ASKED QUESTIONS

What is the purpose of the nurse visit? We want to ask you a few questions about your health. With your permission we would like to take a few measurements and, if you consent, a small blood sample.

Why should I take part? We need information from a wide range of people to get a true picture of the eating habits and health status of people in the UK. The information collected at the nurse stage completes the picture with the dietary information you provided. It helps us to understand how diet can affect health outcomes and nutritional status.

What will happen to any information I give? Any information you give us is treated in strict confidence. The published results of the study will never include any names or addresses. The information collected is used for statistical and research purposes only and will be dealt with according to the principles of the 1998 Data Protection Act.

Contact number and contact names If you would like to talk to someone about the study, please phone NatCen on freephone 0800 652 4572. Thank you for helping us with our survey so far. We would now like to ask you to take part in the nurse visit.

Any questions? Our nurse will try to answer any questions you have. Or, if you like you can email or speak to one of us using the contact details below:

Beverley Bates NDNS Research Director NatCen Social Research, Kings House, 101-135 Kings Road, Brentwood, CM14 4LX

Freephone: 0800 652 4572

Dr Sumantra Ray Senior Medical Advisor, MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL

Telephone: 01223 426356

Thank you very much for your time and help with this important survey.

What will happen to my results? If you are interested, we will send you the results of some of the tests (e.g. vitamin and mineral levels, cholesterol, haemoglobin). As a thank you for providing a blood sample we will give you a £20 gift card.

We will ask for written consent to tell your GP the results from your blood tests that are clinically relevant. If you wish we will also tell them your blood pressure and body mass index (BMI) measurements. If we tell your GP this could affect your future insurance status (e.g. for life insurance or private medical insurance).

If you are aged 16 years and over, you can choose not to receive your test results or have them sent to your GP.

You can take part in as few or as many measurements as you feel happy with and you are free to withdraw at any time. Your personal details and test results will be kept strictly confidential and no one looking at the study findings will be able to identify you or your household in any way.

For more info have a look at www.nationaldiet.co.uk The nurse will ask you a few questions about your health and explain a bit more about the other parts of the nurse visit which are:

**Blood pressure**

The nurse will ask if you are willing to have your blood pressure taken using an inflatable cuff that goes around the upper arm.

This measures how hard the heart pumps blood around the body. Blood pressure is important because the higher a person’s blood pressure is, the higher their risk of health problems in the future. If you agree, we can send a copy of your blood pressure reading to your GP.

**Demispan measurement**

If you are aged 65 years or over, or you did not have your height measured at the interviewer visit, the nurse will ask if you are willing to have your demispan measured. Demispan is half the distance between your hands outstretched to either side. This is measured with a tape measure when fully clothed.

A Demispan measurement gives an estimate of your height.

**Waist and hip measurement**

The nurse will ask if you are willing to have your waist and hip measurements taken. This is done using a tape measure when fully clothed.

Waist and hip measurements tell us about the distribution of weight over the body.

**A blood sample**

The nurse will ask if you would be willing to provide a small blood sample. If you provide a blood sample, we will ask whether you are willing for any remaining blood to be stored for future research. Blood samples are important to the survey as they can tell us very important information, that we cannot get in any other way, about nutritional health, and about the ways in which our body benefits from the food we eat.

You will be asked to fast overnight. This means not eating or drinking anything other than water for a minimum of 8 hours before the blood sample is taken. If you are diabetic the nurse will speak to you about providing a non-fasting sample. The nurse will visit in the morning, at a time that is convenient for you. The nurse will take no more than 35ml (2.5 tablespoons) of blood. We will ask you to sign a consent form to say you agree to providing a blood sample.

Our nurses are very experienced and it is the same as giving a blood sample at the doctor’s. You should hardly feel anything other than a scratch. If you would like, we can spray your arm with Cryogesic spray to numb it (or Ametop gel if under 16 years) – the nurse can explain more about this. Will I get any results from my blood sample?

We are usually able to give you feedback about some of your blood sample results, if you would like this. We may also be able to send some of your results to your GP if you agree.

It's unlikely that you will have any adverse effects, however if you experience any of the following, you should seek further help, for instance from your GP or NHS Direct:

- Severe pain
- Numbness or persistent ‘pins and needles’ in the arm, hand or fingers
- Swelling which is large or increasing in size
- Painful redness/inflammation.

Any questions?

Our nurse will try to answer any questions you have. Or, if you like you can email or speak to one of us using the contact details below:

Beverley Bates\
NDNS Research Director\
NatCen Social Research,\
Kings House,\
101-135 Kings Road,\
Brentwood,\
CM14 4LX\
Freephone: 0800 652 4572

Dr Sumantra Ray\
Senior Medical Advisor,\
MRC Human Nutrition Research,\
Elsie Widdowson Laboratory,\
120 Fulbourn Road,\
Cambridge,\
CB1 9NL\
Telephone: 01223 426356

Thank you very much for your time and help with this important survey.

For more info have a look at www.nationaldiet.co.uk

National Diet and Nutrition Survey (NDNS)

Giving a blood sample\
Frequently asked questions

The NatCen survey nurses and midwives follow ‘best practice’ principles which meet current national standards used within the NHS.

This leaflet gives answers to some of the questions people often ask about giving a blood sample.

If you have any further queries, please ask the NatCen survey nurse.

For more info have a look at www.nationaldiet.co.uk Why do you need to take a blood sample? The analysis of the blood samples will tell us a lot about the health of the general population. It adds importantly to the information you have already given us. Your survey nurse will explain about the tests we will carry out for this particular study.

What about hygiene standards? The survey nurses maintain the highest hygiene standards to reduce any risk of infection. We use a new sterile needle and new tubes for every person.

Is any special equipment needed? Before a needle is inserted into your vein, the survey nurse will apply a tourniquet (a band put round your arm to control your blood flow). This keeps more blood in the vein, making it easier for the nurse to see and access it.

What if I feel faint? Anyone might feel faint during or immediately after giving a blood sample, although most people don’t. If you begin to feel faint at all, tell the nurse as soon as possible, if you can. The nurse will be watching you for any signs of fainting, and if necessary will stop taking the blood sample.

If you actually faint, which can happen but is very unlikely, you will be advised not to drive for at least 30 minutes once you have come round.

Does it hurt? Blood sampling may cause some discomfort. Very rarely, you may feel a stronger sensation. Please tell the nurse immediately if you are at all concerned. We may be able to use a spray or a gel to numb the arm (the nurse has more information about this).

How long should I keep the dressing on afterwards? The nurse will apply a dressing after taking the sample. You should leave this dressing on for at least 30 minutes after the blood sample has been taken.

Will I get a bruise? Bruising occurs when blood leaks from a vein into the surrounding tissues. The nurse will make every attempt to reduce bruising through applying pressure to the affected vein after taking the blood sample. However, bruising does sometimes occur. This may be slightly uncomfortable for a day or so after giving the sample but usually no action is required. If it gets worse (for example if the bruise hurts more or gets much bigger), you should seek further help, for instance from your GP or NHS Direct.

Should I avoid any activities after giving the sample? To reduce any risk of bruising, where possible we suggest you avoid any heavy lifting or strenuous exercise for the rest of the day you give your blood sample. The aim of the study is to keep track of the diets and nutritional health of people in the UK so that changes can be made where necessary to try and help keep the population healthy.

Why provide a blood sample?

The only way we know if someone has enough vitamin D for their body’s needs is to measure it in the blood. This is one of the most important things we look at in the blood sample because the diet tells us so little about it. It is especially important that we measure vitamin D in children, particularly since many children spend more time indoors these days.

We get vitamin D from two places. We get it from some foods but importantly the body also makes vitamin D when sunshine reaches our skin. We need vitamin D for healthy bones.

Any questions?

Our nurse will try to answer any questions you have. Or, if you like you can email or speak to one of us using the contact details below:

Beverley Bates NDNS Research Director NatCen Social Research, Kings House, 101-135 Kings Road, Brentwood, CM14 4LX

Freephone: 0800 652 4572

Dr Sumantra Ray Senior Medical Advisor, MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL

Telephone: 01223 426356

Thank you very much for your time and help with this important survey.

For more info have a look at www.nationaldiet.co.uk Iron is needed to help carry oxygen around the body. A lack of iron leads to anaemia, causing tiredness, and can affect concentration, intellectual performance and how well you can fight infections.

The amount of iron a person needs is different for different ages and for males and females. Iron is found in many foods such as cereals and some vegetables, but the iron in meat is much better absorbed than iron from other foods. All of these things mean that measuring iron in blood is the best way to know if people are getting enough iron.

It is not uncommon for people to have too little iron – this is called ‘iron deficiency’. To prevent iron deficiency being a major problem, it is important we know about iron levels in different age and sex groups so the right advice can be given to the right people.

What blood can tell us about Iron

Iron is needed to help carry oxygen around the body. A lack of iron leads to anaemia, causing tiredness, and can affect concentration, intellectual performance and how well you can fight infections.

The amount of iron a person needs is different for different ages and for males and females. Iron is found in many foods such as cereals and some vegetables, but the iron in meat is much better absorbed than iron from other foods. All of these things mean that measuring iron in blood is the best way to know if people are getting enough iron.

It is not uncommon for people to have too little iron – this is called ‘iron deficiency’. To prevent iron deficiency being a major problem, it is important we know about iron levels in different age and sex groups so the right advice can be given to the right people.

What is the benefit to me and to others?

If you wish to receive them, we will send you the results of your or your child’s blood measurements. Also, with your agreement, we will send them to your GP. If a result suggests there may be a problem, we will advise you to see your GP. The GP can then follow up what we found. Vitamin D and indicators of iron levels are examples of what we can feed back to you. You will find more information about these below and on the next page.

What blood can tell us about Iron

Iron is needed to help carry oxygen around the body. A lack of iron leads to anaemia, causing tiredness, and can affect concentration, intellectual performance and how well you can fight infections.

The amount of iron a person needs is different for different ages and for males and females. Iron is found in many foods such as cereals and some vegetables, but the iron in meat is much better absorbed than iron from other foods. All of these things mean that measuring iron in blood is the best way to know if people are getting enough iron.

It is not uncommon for people to have too little iron – this is called ‘iron deficiency’. To prevent iron deficiency being a major problem, it is important we know about iron levels in different age and sex groups so the right advice can be given to the right people.

What about children?

For a number of nutrients children are more likely to have low amounts. Also, children may avoid certain foods. It is especially important that we know if the number of children with low levels of important nutrients is changing in the UK. We can only do this if we measure nutrient levels in their blood and to do this we need blood samples from children.

We know it is not much fun for children to have blood taken. Some children may be frightened of needles and think it is going to be very sore. We can help make it easier by using a cream or spray to numb the arm and by using specialist nurses who take blood from children all the time.

Why provide a blood sample?

The food and drink diary you provided will help us know about the eating habits of people in the UK, the calories they eat and their intake of nutrients like fat, protein and carbohydrate, minerals such as iron, calcium and zinc, and vitamins, including B, C, A and E.

However, the amount of vitamins and minerals absorbed varies from person to person depending on the types of foods the nutrient is in, other foods eaten at the same time, and natural differences in the way different people’s bodies work.

Only by measuring the same vitamins and minerals in blood samples can we see if people in the UK have enough of these important nutrients.

We can also look at people’s risk for certain conditions. Serum cholesterol, for example, tells us about risk for heart disease, and glucose tells us about diabetes. We cannot tell these things from just looking at your food and drink diary. The blood sample will help us complete the picture. There are some other examples of the vitamins and minerals we can look at in your blood sample on the next page.